The present invention relates to an improvement in resuscitation aids, particularly devices for facilitating mouth-to-mouth resuscitation, of the type described in U.S. Pat. No. 4,998,530 and application Ser. No. 07/653,638 now U.S. Pat. No. 5,095,898.
As used herein, mouth-to-mouth resuscitation refers to methods in which air is forced from the lungs of a rescuer into the lungs of a victim of stopped breathing at regular intervals to provide the interchange of air necessary for respiration. If a victim of stopped breathing is to be saved from death, resuscitation must be started promptly after the cessation of breathing. At times, the heart may also have stopped, in which case simultaneous cardiac resuscitation will also be necessary.
Mouth-to-mouth resuscitation, frequently referred to as the "kiss of life", is a technique which is known to a significant portion of the population, particularly since it is not difficult to learn and does not require special equipment.
Unfortunately, the classic mouth-to-mouth technique requires direct contact between rescuer and victim, and many individuals find this aspect of the technique objectionable. Such objections have become even more prevalent because of the fear of transmission of the AIDS virus, given that a victim is often a stranger to a potential rescuer. Because of this fear, even trained paramedic personnel have become reluctant to administer mouth-to-mouth resuscitation.
Many devices have been developed for performing resuscitation in which no mouth-to-mouth contact is required between rescuer and victim. These devices usually involve inserting some type of tube into the airway of a victim. Among these devices are intubation devices, esophageal obturator airways and "bag valve mask" devices.
In order for such devices to be fully effective, they should establish an effective seal over the victim's mouth when air is being breathed into the victim. Many of the known devices are incapable of forming such a seal.
In addition, many known devices are relatively complicated and expensive so that they could not be made widely available for general use. Since resuscitation must be started within minutes after a stoppage of breathing, devices which cannot be made widely available and/or which can only be used by a small number of highly trained personnel are of little practical value.
Thus, mouth-to-mouth resuscitation remains the technique which offers the greatest hope of assistance to a victim of stopped breathing. Because the lips and associated facial muscles of such a victim are flaccid, virtually no known resuscitation aid can produce a perfect seal with the victim's lips. A nearly perfect seal can be created, however, if the rescuer purses his lips and then covers the victim's mouth. Such perfect seal is due in large measure to the ability of the rescuer to close his lips over the mouth area of the victim and thus perfectly conform to that area.
The invention disclosed in U.S. Pat. No. 4,998,530 resolves many of these problems by providing a device which includes: a sheet of a flexible material forming a barrier to micro-organisms, the sheet being dimensioned to completely cover the victim's mouth, the sheet having an opening and a shaped portion which surrounds the opening and is shaped to allow the rescuer's lips to form an air-tight seal with the victim's lips when the rescuer is blowing air into the victim's mouth, the sheet, including the shaped portion, being formed to permit the victim to exhale without obstruction when the rescuer's lips are withdrawn from the sheet; a tubular member defining a confined air passage extending through the opening and having a first portion located to be inserted into the victim's mouth and over the victim's tongue when the sheet is in place and a second portion located to be inserted into the mouth of the rescuer; and means defining a one-way valve fastened to the tubular member for permitting free passage of air only from the rescuer to the victim.
Copending application Ser. No. 07/653,638 is directed to a modification of the embodiment disclosed in U.S. Pat. No. 4,998,530, according to which the valve is supported by the portion of the tubular member which is located to be inserted into the mouth of the rescuer. Since the valve is of a type which is capable of being inadvertently opened by lateral deformation of the tubular member, it was noted that if the valve is supported by the above-described portion of the tubular member, the valve is less likely to be inadvertently opened by deformation forces imposed on the tubular member.
In addition, as disclosed in copending application Ser. No. 07/653,638, proper operation of the valve can be further insured by the provision of a rigid tubular member which preferably extends along at least a substantial part of the tubular member portion which is to be inserted into the mouth of the rescuer and at least a substantial part of the portion of the tubular member which is to be inserted into the victim's mouth and over the victim's tongue when the device is in use. This rigid member serves as a bite block which prevents the victim from closing the air passage and prevents, to a substantial extent, the rescuer from deforming the valve.
However, further study has revealed that under certain circumstances, the valve can be opened by physical deformation of the tubular member which defines the air passage. For example, it has been found possible to manually impose axial forces, or forces having an axial component, on that tubular member which can, under certain circumstances, produce an opening of the valve at a time when the rescuer is not insufflating the victim.